The best time to workout, of course, is whatever time works for you. But if you’re not much of a morning person, you might’ve been stymied by old fashioned rules like “you should never exercise late at night.” Who came up with this? We’re not really sure. Our only guess is that it originated with some up-and-at-‘em personal trainers who prefer those early morning sweat sessions. But there’s no hard science that says your workout is only beneficial before breakfast. And the myth that a late-night workout will disrupt your sleep is just that—a myth. A study published in the Journal of Sleep Research recently concluded that “vigorous late-night exercise does not disturb sleep quality.” At all.
In fact, there have been several scientific analyses which proved that a good workout at night could actually help you sleep better, longer and deeper. Plus, you might be surprised (and relieved) to know that there are a number of other benefits you can reap from training in the p.m.—everything from increased weightloss to improved heart health. So go ahead and sleep in, because hitting the gym after sunset might be the best swap you make to your fitness routine.
From a practical standpoint, you’ll likely notice that the gym is a lot less crowded in the evening. If you've been a little nervous about attempting a new-to-you machine around others, this is an ideal time to try it. With more space to move around, you’ll have less waiting around for machines and dumbbells, which in turn, makes any workout more efficient.
If you tend to feel like you’re dragging in the mornings, you likely can’t give it your all. A late-night session will likely allow you to push yourself further. Researchers have determined that muscles have circadian rhythms and that muscle strength is at its highest later in the day. Meanwhile, trainers and physiologists agree that we tend to have a higher body temperature later in the day, and this contributes to greater flexibility and muscle strength.
What’s more, you’ll likely notice that you have more endurance later in the day. Research has shown we can go up to 20% longer in the evenings, and at a higher intensity. A highly-respected study from England's University of Birmingham found that our performance peaks 11 hours after waking for late risers. Even early birds fare better later: They did best aerobically about six hours after waking. And when you can go harder, longer, faster, stronger, you'll see the payoff quicker.
Of course, there’s no denying that getting in that workout first thing in the morning will give you a boost of confidence and accomplishment. And it also ensures that you exercise without getting distracted or sidetracked with other obligations. On the flip side, sweating out all the stress from a hectic day allows you to temporarily disconnect from the day's bullshit while also wearing you out and getting you ready to rest up (rather than let your mind race as you prepare for sleep).
As an added bonus, you may actually see faster results. Muscle function and strength peak in the p.m., and fluctuating hormones may make late-day workouts more effective for toning up. High levels of cortisol in the morning can prevent muscle growth, but increased testosterone in the evening boosts the body’s ability to grow new muscle tissue. And consistent evening workouts might just be the link to connect the trifecta of calorie-burn, improved sleep and reduced stress to unlock the key to fat loss. Because getting rid of stubborn fat has as much to do with managing stress and sleep as it does with time on the treadmill.
So we now know that you’ll be able to push yourself harder and pack on more muscles after dark, but what about the actual health benefits? Well, it turns out that when it comes to resistance training, a nighttime workout is even more beneficial for the heart than activities done during daylight hours. Jill Kanaley, professor at the University of Missouri Department of Nutrition and Exercise Physiology, published a study that concluded that “resistance exercise has its most powerful effect on reducing glucose and fat levels in one's blood when performed after dinner.”
Our suggestion? Have a good, high-protein meal after work, rest for an hour or so, and then hit the gym to get in on all these fat-burning, muscle-building, stress-reducing and life-extending benefits.